With the aid of such instruments, it is possible to carry out repairs on, for example, the power plant blades of turbine power units, without having to undertake time-consuming and therefore expensive dismantling and reassembly. Inspection holes are provided in the turbine housing for this purpose, and instruments of this type can be introduced through these holes so that, for example, small impacts on the leading or trailing edges of the blades can be worked.
An instrument of the type mentioned above is known, for example, from EP 0 426 527 A1 (U.S. Pat. No. 5,102,221). The fundamental unit of this instrument is a technoscope that is provided with a tool carrier that runs through the shaft and that has a swing-out head as tool holder. From the handle of the instrument, this tool holder can be swung out by means of an activating rod running through the carrier, and can accommodate a working tool at its end. The tool carrier is movable in longitudinal oscillations by means of a motorized drive, so that working can be undertaken by means of the back-and-forth oscillating movement of the working tool. The disadvantage with this instrument is that only a small working intensity is attainable with it, which makes the working relatively time-consuming.
Another known instrument has a technoscope, equipped with connections for a camera and illumination, that has a rigid shaft and a flexible tip whose bending can be controlled. This technoscope is modified in such a way that an axially extending, rotating tool accommodation is carried in the tip; this tool accommodation is drivable via a flexible rod running through the shaft and by means of a motor placed in the handgrip of the technoscope. What is disadvantageous about this instrument is that it cannot be angled tightly enough, and the lack of rigidity inherent in the system does not allow precise guidance during the working operations.
It is an object of this invention to create a robust instrument with a head that can be angled and can accommodate a tool, which can be guided precisely even at comparatively high levels of working intensity.